Influence of Light and Temperature on the Reproductive Cycle of the Eastern Brook Trout, Salvelinus fontinalis (Mitchill)

1963 ◽  
Vol 20 (4) ◽  
pp. 859-897 ◽  
Author(s):  
Nancy E. Henderson
Keyword(s):  
Environmental Factors ◽  
Seasonal Changes ◽  
Brook Trout ◽  
Ovarian Development ◽  
Salvelinus Fontinalis ◽  
Average Diameter ◽  
Gonadal Development ◽  
Light Regime ◽  
Male And Female ◽  
First Time

Brook trout were exposed to photoperiods ranging from 4 to 20 hours per day and were held either at 8.5 °C or at 16°. The average diameter of the ova was used as an index of ovarian development while testicular maturation was determined from histological preparations.The gonadal cycles of both male and female trout were markedly affected by different photoperiodic regimes. The influence of long or short photoperiods depends upon the phase of gametogenesis in progress at the time and on the photoperiod in effect during earlier stages of the gonadal cycle. Evidence is presented which suggests that the maturation cycle of the gonads may be regulated by the normal seasonal changes of day length.An accelerated light regime can hasten the time of functional maturity in adult trout, but is without effect when applied to maturing fish in which gametogenesis is taking place for the first time. It is suggested that a stimulative effect of environmental factors is dependent upon maturation of the hypothalamic-hypophyseal mechanism.The rate of gonadal development is the same at 16° as it is at 8.5° provided the fish are exposed to natural day lengths. If fish are subjected to long or to short photoperiods, the gonadal response at 16° is quite different from that at 8.5°.

Monthly variations in the profile of sex steroids and gonadal development of brook trout (Salvelinus fontinalis Mitchill) during puberty in Tasmania

2014 ◽  
Vol 62 (3) ◽  
pp. 200 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Salvelinus Fontinalis ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
First Year ◽  
Female Fish ◽  
Oocyte Stage ◽  
Monthly Variations

Puberty is an important reproductive event that has not been studied in brook trout in the Southern Hemisphere. The present study describes the histological development of gonads and variations in the levels of oestradiol-17β (E2), testosterone (T) and 11-ketotestosterone (11-KT) during the first year of male and female brook trout. The study started when the trout were at an age of 8 months (n = 10) and continued until they were 15 months. Of the males, 60% attained puberty at an age of 14 months. The peak of the gonadosomatic index in males was observed at 15 months of age (3.0 ± 0.9%). Female fish did not achieve maturation during their first year and ovarian development did not progress beyond the vesicular oocyte stage within the study period.

Differences in sexual maturity and fall emigration between diploid and triploid brook trout (Salvelinus fontinalis) in an Adirondack lake

1997 ◽  
Vol 54 (8) ◽  
pp. 1808-1812 ◽  
Author(s):  
J A Warrillow ◽  
D C Josephson ◽  
W D Youngs ◽  
C C Krueger
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Gonadal Development ◽  
Spawning Habitat ◽  
Diploid Males ◽  
Reproductive Risk ◽  
Spawning Areas ◽  
In Captivity ◽  
Adirondack Lakes ◽  
Triploid Fish

High levels of emigration coincident with maturity and spawning have been reported from brook trout (Salvelinus fontinalis) populations in Adirondack lakes. These lakes typically had few spawning areas and required stocking to maintain populations. We compared diploid and triploid brook trout to identify differences in gonadal development and emigration. Age 1 + and 2 + diploid and triploid brook trout held in captivity were examined internally for gonadal development. More diploid trout were mature than triploid fish (p < 0.01). Of triploid brook trout that matured, all were males. Yearling diploid and triploid brook trout were also stocked into a lake that had an outlet but no spawning areas. During the fall spawning season, only mature yearling triploid males, diploid males, and diploid females were caught in an outlet trap. No triploid females were caught. A greater proportion of diploids emigrated than triploids (p < 0.01). Triploidy in females arrested emigration by preventing sexual maturation. Triploid male brook trout should not be stocked because they can pose a reproductive risk to wild brook trout downstream from lakes. Stocking triploid females could reducefall emigration and thus reduce the loss of catchable brook trout from Adirondack lakes with outlets and little spawning habitat.

Abundance and Potential Pathology of Parasites Infecting Salmonids in Canadian Maritime Hatcheries

1974 ◽  
Vol 31 (6) ◽  
pp. 1031-1036 ◽  
Author(s):  
G. M. Hare ◽  
C. Frantsi
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Brook Trout ◽  
Parasite Species ◽  
Salvelinus Fontinalis ◽  
Infection Intensity ◽  
Salmo Gairdneri ◽  
Host Age ◽  
Intensity Of Infection ◽  
First Time

Seventeen parasite species (3 protozoans, 11 helminths, 2 arthropods, and 1 mollusc) were collected from 317 Atlantic salmon (Salmo salar), 207 brook trout (Salvelinus fontinalis), and 34 rainbow trout (Salmo gairdneri) in the 13 Canadian Maritime hatcheries during 1972. Four parasites, Camallanus oxycephalus, Pomphorhynchus bulbocolli, Hydrachna sp., and a glochidium, were recorded from Atlantic salmon for the first time. Incidence and intensity of infection were high for Trichophyra piscium, Diplostomulum spathaceum, and glochidia infecting salmon and for Acanthocephalus lateralis and Salmincola edwardsii infecting brook trout. Infection intensity of Apophallus imperator, D. spathaceum, S. edwardsii, and glochidia increased with host age. Apophallus imperator and S. edwardsii were host specific to brook trout and the glochidium was host specific to salmon. Sterliadochona tenuissima and A. lateralis were more abundant in brook trout than in salmon. Pathology was associated with infections of Hexamita salmonis, D. spathaceum, A. lateralis, and S. edwardsii.

Diel and Seasonal Changes in Resting Levels of Various Blood Parameters in Brook Trout (Salvelinus fontinalis)

1992 ◽  
Vol 49 (5) ◽  
pp. 870-877 ◽  
Author(s):  
Céline Audet ◽  
Guy Claireaux
Keyword(s):  
Thyroid Hormones ◽  
Seasonal Changes ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Plasma Osmolality ◽  
Blood Parameters ◽  
Seasonal Cycles ◽  
Temperature Plasma ◽  
Diel Cycles ◽  
Natural Photoperiod

Plasma osmolality, chloride, glucose, Cortisol, thyroid hormones, and blood hematocrit all varied seasonally in freshwater-adapted, age 1 + brook trout (Salvelinus fontinalis) kept under natural photoperiod and water temperatures. In addition, plasma osmolality, Cortisol, and thyroxine all displayed diel cycles that differed from month to month. High Cortisol levels were related to sexual maturation and possibly to low water temperatures. Seasonal cycles of plasma thyroid hormones did not seem to be influenced by water temperature. Plasma osmolality, chloride, glucose, and thyroxine showed small but significant seasonal changes similar to the variations observed at the time of smoltification in other salmonid species.

Prolactin Cell Cytology, Plasma Electrolytes, and Whole-Body Sodium Efflux in Acid-Stressed Brook Trout (Salvelinus fontinalis)

1988 ◽  
Vol 45 (7) ◽  
pp. 1212-1221 ◽  
Author(s):  
J. N. Fryer ◽  
W. H. Tam ◽  
B. Valentine ◽  
R. E. Tikkala
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acid Exposure ◽  
Whole Body ◽  
Plasma Sodium ◽  
Prolactin Cells ◽  
Sodium Efflux ◽  
Male And Female ◽  
Prolactin Cell ◽  
Body Sodium

Twelve-month-old brook trout (Salvelinus fontinalis) of both sexes were exposed to acidified water (pH 4 5) for a period of 52 d. Ultrastructural morphometric studies of the prolactin cells of the pituitaries of acid-stressed female trout revealed a reduction, after a latent period of about 1 wk, in prolactin cell area, cytoplasmic area and nuclear area which gradually recovered to control values by day 52 of acid exposure. In both male and female trout, acid exposure resulted in significant decreases in plasma osmolarity, and plasma sodium, which gradually returned to control values by day 52 of the study. Total plasma calcium was not altered by acid exposure in either male or female trout. For both male and female trout, acid exposure resulted in transient elevations in haematocrit and a prolonged suppression of blood pH. The whole-body sodium efflux for trout introduced into dechlorinated tap water or distilled water was significantly greater at pH 4.5 than at pH 7.35. Possible relationships between the acid-induced inhibition of the secretory activity of the prolactin cells and impairments in osmotic and ionic regulation observed in acid-stressed trout are discussed.

Environmental factors correlate with hybridization in stocked brook charr (Salvelinus fontinalis)

2012 ◽  
Vol 69 (5) ◽  
pp. 884-893 ◽  
Author(s):  
Amandine D. Marie ◽  
Louis Bernatchez ◽  
Dany Garant
Keyword(s):  
Environmental Factors ◽  
Brook Trout ◽  
Propagule Pressure ◽  
Salvelinus Fontinalis ◽  
Relative Effect ◽  
Genetic Integrity ◽  
Wild Populations ◽  
Brook Charr ◽  
The World

Stocking is a common practice throughout the world that may increase hybridization between wild and domesticated populations. Stocking intensity alone does not always fully explain the observed patterns of hybridization, suggesting that the intensity of hybridization may be modulated by environmental factors. Using brook charr (i.e., brook trout, Salvelinus fontinalis ) as a model, the objective of this study was to assess the relative effect of environmental factors and stocking intensity on the level of hybridization observed within brook charr from 15 lacustrine populations of two wildlife reserves in Quebec, Canada. The level of hybridization significantly increased with (i) the number of stocking events, (ii) a reduction in both surface area and maximum depth of lakes, and (iii) a reduction in dissolved oxygen and an increase in temperature and pH. These results suggest that levels of hybridization were affected by the availability and quality of lacustrine habitats as well as by the extent of propagule pressure. Our study provides the first demonstration that knowledge of environmental features may help predict the effects of stocking on the genetic integrity of wild populations.

scholarly journals Seasonal changes in reproductive cycle of female fresh water prawn, Macrobrachium dayanum (Henderson) from river Gomti, Lucknow (India)

2019 ◽  
Vol 11 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Rashmi Tripathi ◽  
Sanjive Shukla ◽  
U D Sharma
Keyword(s):  
Fresh Water ◽  
Reproductive Cycle ◽  
Seasonal Changes ◽  
Gonadal Development ◽  
Experimental Animals ◽  
Two Peaks ◽  
Reproductive Activities ◽  
First Time

The present study was conducted on the experimental animals, Macrobrachium dayanum (Henderson) (Crustacea: Decapoda) to analyze the seasonal changes in reproductive cycle of female, found at different locations in river Gomti (26°55´; 80°59´ E), in and around Lucknow (U.P. India). The reproductive activities were found in cyclic manner in M.dayanum, which breeds continuously throughout the year but with two distinct peaks one major in the month of May-July and one minor in the month of January – Feburary. Five stages of Oogenesis i.e. proliferative, meiotic, previtellogenic, vitellogenic and resorbtion or atretic oocyte phase have been recorded in M. dayanum. Mature ova were noticed in two peaks i.e. major in month of July – August and September and minor in months of February and March. Histoarchitecture of hepatopancreas showed seasonal changes in accordance with the gonadal development. The reproductive cycle of M.dayanum is reported for the first time and very little work is known on the seasonal changes with respect to reproduction and its correlation with hepatopancreas.

A review of the little known genus Wockia (Lepidoptera: Urodidae) in Russia

2016 ◽  
Vol 25 (1) ◽  
pp. 173-179
Author(s):  
S.Yu. Sinev
Keyword(s):  
East Asia ◽  
Zoological Institute ◽  
Female Genitalia ◽  
Palaearctic Species ◽  
Male And Female ◽  
First Time ◽  
Subjective Synonym

Three species of the genus Wockia Heinemann, 1870, which are so far known in Russia are reviewed; their male and female genitalia are illustrated, and a key for identification is provided. Two species, W. koreana Sohn, 2008, and W. magna Sohn, 2014, which were recently described from East Asia, are for the first time reported from Russia. The investigation of the holotype of W. funebrella Heinemann, 1870, discovered in the collection of the Zoological Institute RAS (St Petersburg), confirmed that this species is a junior subjective synonym of W. asperipunctella (Bruand, 1851). The distribution of Palaearctic species of the genus is discussed shortly.

Sign in / Sign up

Export Citation Format

Share Document